CIS Tax Rebate Calculator

How does the calculator estimate my CIS Tax Rebate?

The CIS tax rebate calculator takes your total gross self employed income figure and deducts your expenses to create your profit received. Your tax free personal allowance is then deducted from your profit to produce your total income on which tax is due.

The calculator then works out a CIS tax refund estimation by working out the difference between the amount of CIS tax already deducted by your contractor and the amount of tax that is owed on your total income on which tax is due.

The calculator does not take into consideration any other income, for example from PAYE work or any benefits like JSA.

Please note, our CIS tax rebate calculator only gives you an estimation of what you might be entitled to.

What is a CIS tax rebate?

If you’re working in construction under a contractor, they typically only employ subcontractors who have registered for the CIS scheme.

Without CIS registration, contractors will automatically withhold 30% tax from your monthly earnings which is usually more than your actual tax liability.

Joining the CIS scheme lowers the automatic deduction to 20% which is often still too much tax which means you can claim a CIS tax rebate back from HMRC by completing a self assessment tax return.

What do I need to apply for a CIS tax refund?

To apply for your CIS tax refund you must complete your CIS tax return and you’ll need information on all of your income and outgoings.

CIS tax return necessary records:

• A record of your self-employed income like CIS statements from your contractor.
• PAYE employment information for example a P60 or P45.
• Any jobseekers allowance or ESA if claimed.
• Proof of any expenses incurred like a record of your mileage if you used your own car to travel to temporary sites.

Your records should be kept digitally by using third party accountancy software or in an alternative digital format for a six year period.

Your CIS tax return should only include allowable expenses which can be evidenced if HMRC ask. The office can check your tax return before or after a CIS tax refund has been repaid.

If the tax office review your tax return after your CIS refund has been repaid and find that your return is incorrect a request will be made for you to repay some or all of the tax refund received.

Our free CIS tax refund guide is here to explain more about the construction industry scheme and what it means for you.

CIS tax returns

A CIS tax return has to be received by HMRC to allow for your CIS refund to be repaid by HMRC.

You will need your ten digit unique taxpayer reference number (UTR) which you would have received when you registered for self assessment.

It is usually best to submit your tax return online although you can download a paper copy and send it to HMRC through the post.

If you are a new CIS sub contractor and have not yet registered with HMRC you can do so online and they will set you up as a construction industry scheme (CIS) sub contractor.

CIS tax return deadlines

The CIS tax return deadlines are strict and follow normal self assessment timescales. You normally must submit your tax return on or before the 31st January after the tax year in question has ended.

The deadline is the 31st October if you decide to submit your tax return on paper through the post.

If you don’t send your tax return to HMRC on time you will receive an immediate late filing penalty which can be appealed if you have a reasonable excuse. Further late filing penalties can be issued after 3 months, six months and twelve months.

In cases where you owe HMRC tax you can incur late payment penalties and interest as well as late filing penalties.